...there are 4 sets of louvers on the face of the dam that cover tunnel openings for circulating air throughout the dam for workers (and visitors)...
we'll walk that tunnel later and peek out down river through the louvers...

...this is a tunnel that goes out to 1 set of louver on the face of the dam that cover tunnel openings for circulating air throughout the dam for workers
(and visitors)... height in tunnel is 5'10"... duck you suckers...